CHARLES JOHNSON was for almost 30 years president of the Flat Earth Society, an American organisation that dissented from the widely held belief that the earth is round.

As a boy he had examined a globe at school and learnt about gravity from his teachers but, notwithstanding the work of Copernicus (whom he dubbed Copernicious), Galileo, Newton et al, Johnson had grave misgivings. From his ranch in the Californian desert - where, admittedly, the world does at times look flat - he published a quarterly newsletter packed with "proof" that mankind has been duped by a scientific conspiracy.

The earth, he claimed, is a flat disc floating on primordial waters, with the North Pole at its centre and Antarctica its circumference; the sun and the moon are each 32 miles in diameter and hover some 3,000 miles overhead - with heaven a further 1,000 miles in the distance; and Australians, he maintained with unassailable logic, "do not hang by their feet underneath the world" - as his antipodean wife was only too happy to testify. According to the Flat Earth Society's teaching, sunrises and sunsets are optical illusions and Nasa's space programme is a hoax.

Numerous historical documents and contemporary studies were called upon to support Johnson's thesis. Even Christ's ascension to heaven purportedly lent the Flat Earth Society credibility: if the earth was in fact a ball spinning in space, there would be neither up nor down. According to detailed and complex calculations undertaken by Johnson and his followers, a round world would throw up a 1,700ft-high hump in the Suez Canal, while the Mediterranean Sea would be 60 miles deep towards the middle. "Obviously water's flat," he told one interviewer. "They're trying to tell you water's bent?"

The society's literature pulls no punches. Its aims are to carefully observe, think freely, rediscover forgotten fact, and oppose theoretical dogmatic assumptions; to help establish the United States of the World on this flat earth; and to replace the religion of science with sanity.

Charles Kenneth Johnson, who dubbed himself "the last iconoclast", was born in San Angelo, Texas, in 1924. For 25 years he served as an aeroplane mechanic in San Francisco. During that time he was in contact with an Englishman, Samuel Shenton, who was president of the Flat Earth Society, previously known as the Universal Zetetic Society. Before his death in 1972, Shenton decreed that Johnson should inherit his work. Entrusted with this lonely task, Johnson moved to a remote ranch near Edwards Air Force Base and picked up the mantle with enthusiasm. At one time the society could boast some 3,500 members, each paying an annual membership fee of $25.

Although the world at large was slow to accept his work, Johnson remained cheerful and unruffled. He enjoyed smoking a cigar while watching the sun set over the flat desert. He was regularly interviewed by curious journalists and was often invited to speak about his subject. He received large quantities of mail, not all of it ridiculing his work, and on one occasion he starred in an ice-cream advertisement.

In 1995 Johnson's home burnt down, destroying most of his records. His wife died the following year and the society became a shadow of its former self. But his work continues both in America and also in Australia, where a local society, run by people standing upright, has been in existence for 14 years.